Method of fabricating a liquid crystal display device having image-displaying and viewing angle-adjusting sub pixels and method of driving the same

ABSTRACT

A liquid crystal display device includes: first and second substrates facing and spaced apart from each other, each of the first and second substrates having an image-displaying sub pixel and a viewing angle-adjusting sub pixel; a thin film transistor corresponding to each of the image-displaying sub pixel and the viewing angle-adjusting sub pixel; a liquid crystal display layer between the first and second substrates, the liquid crystal layer having a negative dielectric constant anisotropy; a first field distortion means in the image-displaying sub pixel; and a second field distortion means in the viewing angle-adjusting sub pixel.

This application claims the benefit of Korean Patent Application No.2008-0053237, filed on Jun. 5, 2008, which is hereby incorporated by areference in its entirety.

TECHNICAL FIELD

The present application relates to a liquid crystal display device, andmore particularly, to an in-cell type liquid crystal display device thatis switchable in viewing angle and a method of driving the in-cell typeliquid crystal display device.

BACKGROUND

A liquid crystal display (LCD) device includes two substrates facing andspaced apart from each other and a liquid crystal layer between the twosubstrates, and uses the optical anisotropy and polarization propertiesof liquid crystal molecules of the liquid crystal layer to produce animage. The liquid crystal molecules have long and thin shapes, andbecause of the optical anisotropy property, the polarization of lightvaries with the alignment direction of the liquid crystal molecules.Accordingly, the LCD device displays an image by controlling thealignment of the liquid crystal molecules as well as the transmittanceof light through the liquid crystal layer due to adjustment of theelectric field applied to the liquid crystal layer. Among the varioustypes of LCD devices, active matrix LCD (AM-LCD) devices that employswitching elements and pixel electrodes arranged in a matrix structureare the subject of significant research and development because of theirhigh resolution and superior suitability for displaying moving images.

According to the property of liquid crystal molecules, the formingmethod of liquid crystal layer and the driving method, the LCD devicesmay be classified into a twisted nematic (TN) mode, a super twistednematic (TN) mode, an optically compensated birefringence (OCB) mode, anin-plane switching (IPS) mode and a vertical alignment (VA) mode.Specifically, the VA mode LCD device using negative type liquid crystalmolecules having a negative dielectric constant anisotropy and avertical alignment layer includes a liquid crystal layer where a longeraxis of the liquid crystal molecules is aligned perpendicular to analignment layer. The VA mode LCD device has advantages in contrast ratioand viewing angle.

Although an LCD device having a relatively wide viewing angle isgenerally preferable, an LCD device having a relatively narrow viewingangle is requested for privacy in a certain circumstance such as anautomatic teller machine (ATM).

Recently, an LCD device which is driven switchably between a wideviewing angle mode and a narrow viewing angle mode has been researchedand developed. FIG. 1 is a cross-sectional view of a liquid crystaldisplay device switchable between a wide viewing angle mode and a narrowviewing angle mode according to the related art. In FIG. 1, an LCDdevice 10 includes first and second liquid crystal cells 20 and 40. Thefirst liquid crystal cell 20 is used as a main cell displaying imagescorresponding to a data signal, and the second liquid crystal cell 40 isused as a switching cell changing a drive mode by controlling a viewingangle according to user's selection.

The first liquid crystal cell 20 includes first and second substrates 22and 24 facing and spaced apart from each other, a first liquid crystallayer 26 between the first and second substrates 22 and 24, and firstand second polarizing plates 28 and 30 on outer surfaces of the firstand second substrates 22 and 24, respectively. The second liquid crystalcell 40 includes third and fourth substrates 42 and 44 facing and spacedapart from each other, a second liquid crystal layer 46 between thethird and fourth substrates 42 and 44, and third and fourth polarizingplates 48 and 50 on outer surfaces of the third and fourth substrates 42and 44, respectively. After the first and second liquid crystal cells 20and 40 are separately formed, the LCD device 10 is completed byattaching the first and second liquid crystal cells 20 and 40.

The LCD device 10 is driven in one of a wide viewing angle mode and anarrow viewing angle mode according to user's selection. When the LCDdevice 10 is driven in the wide viewing angle mode, light along anyviewing angle is transmitted through the second liquid crystal cell 40.As a result, a wide viewing angle image displayed by the first liquidcrystal cell 20 is transmitted through the second liquid crystal cell 40and the LCD device 10 displays the wide viewing angle image. When theLCD device 10 is driven in the narrow viewing angle, light along a frontviewing angle is transmitted through the second liquid crystal cell 40and the second liquid crystal cell displays a white text in a blackbackground along a right-left viewing angle. Accordingly, a wide viewingangle image displayed by the first liquid crystal cell 20 is transmittedthrough the second liquid crystal cell 40 along the front viewing angleand is disturbed by the white text along the right-left viewing angle.As a result, the LCD device 10 displays a narrow viewing angle image.

However, since the LCD device 10 further includes additional elementssuch as the third and fourth substrates 42 and 44, the second liquidcrystal layer 46 and the third and fourth polarizing plates 48 and 50 ascompared with a conventional LCD device, the LCD device 10 is enlargedin weight and volume including thickness. In addition, since light froma backlight unit (not shown) of the LCD device 10 passes through theadditional elements, brightness of the LCD device 10 is reduced.Furthermore, misalignment of the attachment of the first and secondliquid crystal cells 20 and 40 causes deterioration of the LCD device10, and apparatus and process for the conventional LCD device can not beadapted to the attachment step. Moreover, since the second liquidcrystal cell 40 as a switching cell has a passive matrix type, the LCDdevice 10 can not be driven in various narrow viewing angle modes.

SUMMARY

Accordingly, the present invention is directed to a liquid crystaldisplay device and a method of driving the liquid crystal display devicethat substantially obviates one or more of the problems due tolimitations and disadvantages of the related art.

An object of the present invention is to provide an in-cell type liquidcrystal display device which is driven switchably between a wide viewingangle mode and a narrow viewing angle mode without an additionalswitching cell and a method of driving the in-cell type liquid crystaldisplay device.

A liquid crystal display device includes: first and second substratesfacing and spaced apart from each other, each of the first and secondsubstrates having an image-displaying sub pixel and a viewingangle-adjusting sub pixel; a thin film transistor corresponding to eachof the image-displaying sub pixel and the viewing angle-adjusting subpixel; a liquid crystal display layer between the first and secondsubstrates, the liquid crystal layer having a negative dielectricconstant anisotropy; a first field distortion means in theimage-displaying sub pixel; and a second field distortion means in theviewing angle-adjusting sub pixel.

In another aspect, a method of fabricating a liquid crystal displaydevice includes: forming a gate line and a data line on a firstsubstrate, the gate line and the data line crossing each other to definean image-displaying sub pixel and a viewing angle-adjusting sub pixel;forming a thin film transistor connected to the gate line and the dataline; forming a pixel electrode connected to the thin film transistor;forming a color filter layer in the image-displaying sub pixel on asecond substrate; forming a common electrode on the color filter layer;forming a first field distortion means in the image-displaying subpixel; forming a second field distortion means in the viewingangle-adjusting sub pixel; attaching the first and second substratessuch that the pixel electrode and the common electrode face each other;and forming a liquid crystal layer having a negative dielectric constantanisotropy between the first and second substrates.

In another aspect, a method of driving a liquid crystal display deviceincluding: first and second substrates facing and spaced apart from eachother, each of the first and second substrates having animage-displaying sub pixel and a viewing angle-adjusting sub pixel; athin film transistor corresponding to each of the image-displaying subpixel and the viewing angle-adjusting sub pixel; a liquid crystaldisplay layer between the first and second substrates, the liquidcrystal layer having a negative dielectric constant anisotropy; a firstfield distortion means in the image-displaying sub pixel; and a secondfield distortion means in the viewing angle-adjusting sub pixelincludes: when the liquid crystal display device is operated in a wideviewing angle mode, displaying a first image of a wide viewing angle bythe image-displaying sub pixel; and displaying a black at an entireviewing angle range by the viewing angle-adjusting sub pixel, when theliquid crystal display device is operated in a narrow viewing anglemode, displaying the first image of the wide viewing angle by theimage-displaying sub pixel; and displaying the black within a frontviewing angle range and a second image within a predetermined viewingangle range by the viewing angle-adjusting sub pixel.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention.

FIG. 1 is a cross-sectional view of a liquid crystal display deviceswitchable between a wide viewing angle mode and a narrow viewing anglemode according to the related art;

FIG. 2 is a view showing a pixel of a liquid crystal display deviceaccording to a first embodiment of the present invention;

FIGS. 3A and 3B are graphs showing transmittance properties of animage-displaying sub pixel and a viewing angle-adjusting sub pixel,respectively, of a liquid crystal display device according to a firstembodiment of the present invention;

FIG. 4A is a graph showing transmittance property of a image-displayingsub pixel and a viewing angle-adjusting sub pixel of a liquid crystaldisplay device in a wide viewing angle mode according to a firstembodiment of the present invention;

FIG. 4B is a graph showing contrast ratio property of a liquid crystaldisplay device in a wide viewing angle according to a first embodimentof the present invention;

FIG. 5A is a graph showing transmittance property of a image-displayingsub pixel and a viewing angle-adjusting sub pixel of a liquid crystaldisplay device in a narrow viewing angle mode according to a firstembodiment of the present invention;

FIG. 5B is a graph showing contrast ratio property of a liquid crystaldisplay device in a narrow viewing angle according to a first embodimentof the present invention;

FIG. 6 is a view showing images displayed by a liquid crystal displaydevice in a narrow viewing angle mode according to a first embodiment ofthe present invention;

FIG. 7 is a view showing images displayed by a liquid crystal displaydevice in a narrow viewing angle mode according to a second embodimentof the present invention;

FIG. 8 is a graph showing transmittance property of a viewingangle-adjusting sub pixel of a liquid crystal display device accordingto a second embodiment of the present invention;

FIGS. 9 and 10 are plan views showing an array substrate and a colorfilter substrate, respectively, of a liquid crystal display deviceaccording to a third embodiment of the present invention;

FIG. 11 is a cross-sectional view, which is taken along a line XI-XI ofFIGS. 9 and 10, showing a liquid crystal display device according to athird embodiment of the present invention;

FIGS. 12 and 13 are plan views showing an array substrate and a colorfilter substrate, respectively, of a liquid crystal display deviceaccording to a fourth embodiment of the present invention;

FIG. 14 is a cross-sectional view showing liquid crystal display devicesaccording to a fifth embodiment of the present invention;

FIG. 15 is a cross-sectional view showing liquid crystal display devicesaccording to a sixth embodiment of the present invention; and

FIG. 16 is a cross-sectional view showing liquid crystal display devicesaccording to a seventh embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to embodiments which areillustrated in the accompanying drawings. Wherever possible, similarreference numbers will be used to refer to the same or similar parts.

FIG. 2 is a view showing a pixel of a liquid crystal display deviceaccording to a first embodiment of the present invention.

In FIG. 2, a liquid crystal display device 100 includes a plurality ofgate lines 110, a plurality of data lines 120, a plurality of thin filmtransistors (TFTs) T, a plurality of storage capacitors C_(ST) and aplurality of liquid crystal capacitor C_(LC). The plurality of datalines 120 cross the plurality of gate lines 110 to define first, second,third and fourth sub pixels SP1, SP2, SP3 and SP4 constituting a unitpixel for a color image. The TFT T is connected to the gate line 110 andthe data line 120 to correspond to the sub pixel. The storage capacitorC_(ST) and the liquid crystal capacitor C_(LC) are connected to the TFTT, and a data signal is applied to the storage capacitor C_(ST) and theliquid crystal capacitor C_(LC) through the TFT T.

For example, the first, second and third sub pixels SP1, SP2 and SP3 areimage-displaying sub pixels displaying red, green and blue colors,respectively, and each has a wide viewing angle property such that atransmittance has a relatively high value at a wide viewing angle range.In addition, the fourth sub pixel SP4 is a viewing angle-adjusting subpixel displaying a white color and a transmittance of the fourth subpixel SP4 has a relatively high value at a predetermined viewing angle.Each of the first, second, third and fourth sub pixels SP1, SP2, SP3 andSP4 is connected to the respective TFT T and driven by the respectivedata signal.

FIGS. 3A and 3B are graphs showing transmittance properties of animage-displaying sub pixel and a viewing angle-adjusting sub pixel,respectively, of a liquid crystal display device according to a firstembodiment of the present invention. X-axes of the graphs represent aright-left viewing angle or an up-down viewing angle, and y-axes of thegraphs represent a relative transmittance of arbitrary unit (A.U.).

In FIG. 3A, the image-displaying sub pixel such as the first, second andthird sub pixels SP1, SP2 and SP3 (of FIG. 2) has the transmittancecorresponding to the respective data signal. When a maximum value or aminimum value of the data signal is applied to the liquid crystalcapacitor C_(LC) (of FIG. 2) of the image-displaying sub pixel, a whiteor a black is displayed at substantially entire viewing angle range bythe image-displaying sub-pixel. The white and the black represent a highvalue and a low value, respectively, in transmittance. Accordingly, thewhite becomes red, green and blue colors through a color filter layer(not shown) in the first, second and third sub pixels SP1, SP2 and SP3,respectively.

When a voltage is applied to the first, second and third sub pixels SP1,SP2 and SP3 in a normally black type, the transmittance of each of thefirst, second and third sub pixels SP1, SP2 and SP3 is about 100 at afront viewing angle and is over about 30 at a right-left viewing angleor an up-down viewing angle of about −80° to about +80° (thetransmittance is over about 60 at a right-left viewing angle or anup-down viewing angle of about −70° to about +70° and is over about 85at a right-left viewing angle or an up-down viewing angle of about −50°to about +50°). Accordingly, the image-displaying sub pixel such as thefirst, second and third sub pixels SP1, SP2 and SP3 has a property graphof a transmittance to a viewing angle where the transmittance has amaximum value at the front viewing angle (a viewing angle of about 0°)and decreases with increase of the right-left viewing angle or theup-down viewing angle. In addition, the image-displaying sub pixel hasthe transmittance over about 30 within a range of a predeterminedright-left viewing angle or a predetermined up-down viewing angle, forexample, a range of about −80° to about +80°.

When a voltage is not applied to the first, second and third sub pixelsSP1, SP2 and SP3 in a normally black type, the transmittance of each ofthe first, second and third sub pixels SP1, SP2 and SP3 is less thanabout 1 at a right-left viewing angle and an up-down viewing angle ofabout −80° to about +80°. The image-displaying sub pixel in a normallywhite type has a similar property of the transmittance to the viewingangle with the image-displaying sub pixel in a normally black typeexcept opposite display of the white and the black according toapplication of voltage.

As a result, the image-displaying sub pixel such as the first, secondand third sub pixels SP1, SP2 and SP3 has a wide viewing angle propertyregardless of an operation mode of the LCD device such that an image isdisplayed with a relatively high contrast ratio at a right-left viewingangle or an up-down viewing angle of about −80° to about +80°.

In FIG. 3B, the viewing angle-adjusting sub pixel such as the fourth subpixel SP4 (of FIG. 2) has the transmittance of about 0 within an entireviewing angle range or the maximum transmittance at a predeterminedviewing angle according to an operation mode (one of a wide viewingangle mode and a narrow viewing angle mode) of the LCD device by user'sselection. For example, when a voltage is applied to fourth sub pixelsSP4 in a normally black type, the transmittance of the fourth sub pixelsSP4 is about 0 at a front viewing angle (viewing angle of about 0°) andis about 100 at a right-left viewing angle or an up-down viewing angleof about −45° and about +45°. Further, the transmittance of the fourthsub pixel SP4 is over about 30 at a right-left viewing angle or anup-down viewing angle of about −70° to about −20° and of about +20° toabout 70° (the transmittance is over about 60 at a right-left viewingangle or an up-down viewing angle of about −65° to about −25° and ofabout +25° to about 65° and is over about 85 at a right-left viewingangle or an up-down viewing angle of about −55° to about −35° and ofabout +35° to about 35°). Accordingly, the viewing angle-adjusting subpixel such as the fourth sub pixel SP4 has a property graph of atransmittance to a viewing angle where the transmittance has a minimumvalue (for example, about 0) at the front viewing angle (a viewing angleof about 0°) and maximum values at predetermined right-left viewingangles or predetermined up-down viewing angles, for example, about −45°and about +45°, and is between the maximum value and the minimum valueat the other viewing angles. As a result, the property graph has a shapeof a degree-4 curve. The predetermined right-left viewing angles orpredetermined up-down viewing angles may be substantially symmetrical toeach other with respect to the front viewing angle. Specifically, theviewing angle-adjusting sub pixel has the transmittance over about 30within a range of a predetermined right-left viewing angle or apredetermined up-down viewing angle, for example, a range of about −70°to about −20° and about +20° to about +70°.

When a voltage is not applied to the fourth sub pixel SP4 in a normallyblack type, the transmittance of the fourth sub pixel SP4 issubstantially about 0 at a right-left viewing angle or an up-downviewing angle of about −80° to about +80°. The viewing angle-adjustingsub pixel in a normally white type has a similar property of thetransmittance to the viewing angle with the viewing angle-adjusting subpixel in a normally black type except opposite display of the white andthe black according to application of voltage.

The LCD device may be operated in one of a wide viewing angle mode and anarrow viewing angle mode according to voltage application by user'sselection. In the wide viewing angle mode, the viewing angle-adjustingsub pixel such as the fourth sub pixel SP4 displays the black within anentire viewing angle range. Accordingly, the wide viewing angle image ofthe first, second and third sub pixels SP1, SP2 and SP3 is not disturbedby the black and the LCD device displays the wide viewing angle image.In the narrow viewing angle mode, the viewing angle-adjusting sub pixelsuch as the fourth sub pixel SP4 displays the white within apredetermined viewing angle range. Accordingly, the wide viewing angleimage of the first, second and third sub pixels SP1, SP2 and SP3 isdisturbed by the white at the predetermined viewing angle range and theLCD device does not display the wide viewing angle image at thepredetermined viewing angle range due to reduction of contrast ratio. Asa result, the LCD device displays a narrow viewing angle image. Thepredetermined viewing angle range may be determined by a structure ofthe viewing angle-adjusting sub pixel or an applied voltage. Therefore,the operation mode of the LCD device may be switched between the wideviewing angle mode and the narrow viewing angle mode by the voltageapplication to the viewing angle-adjusting sub pixel.

FIG. 4A is a graph showing transmittance property of a image-displayingsub pixel and a viewing angle-adjusting sub pixel of a liquid crystaldisplay device in a wide viewing angle mode according to a firstembodiment of the present invention and FIG. 4B is a graph showingcontrast ratio property of a liquid crystal display device in a wideviewing angle according to a first embodiment of the present invention.X-axes of the graphs represent a right-left viewing angle or an up-downviewing angle, and y-axes of the graphs represents a relativetransmittance of arbitrary unit (A.U.) and a relative contrast ratio ofarbitrary unit (A.U.).

In FIG. 4A, when the LCD device is operated in the wide viewing anglemode, the image-displaying sub pixel such as the first, second and thirdsub pixels SP1, SP2 and SP3 (of FIG. 2) has transmittances correspondingto the data signal, for example, the white or the black. The viewingangle-adjusting sub pixel such as the fourth sub pixel SP4 (of FIG. 2)has the transmittance of about 0 within an entire viewing angle range.The white of the LCD device corresponds to the sum of the transmittanceof the white of the image-displaying sub pixel and the transmittance ofthe viewing angle-adjusting sub pixel in the wide viewing angle mode,and the black of the LCD device corresponds to the sum of thetransmittance of the black of the image-displaying sub pixel and thetransmittance of the viewing angle-adjusting sub pixel in the wideviewing angle mode. Since the transmittance of the viewingangle-adjusting sub pixel in the wide viewing angle mode issubstantially about 0 within an entire viewing angle range, the whiteand the black of the LCD device are substantially the same as the whiteand the black of the image-displaying sub pixel, respectively.

As shown in FIG. 4B, the contrast ratio defined by a ratio of the whiteto the black of the LCD device is over about 20 at a right-left viewingangle or an up-down viewing angle of about −80° to about +80° (thecontrast ratio is over about 30 at a right-left viewing angle or anup-down viewing angle of about −70° to about +70° and is over about 60at a right-left viewing angle or an up-down viewing angle of about −50°to about +50°). Accordingly, the LCD device displays images with arelatively high contrast ratio within a substantially entire viewingangle range in the wide viewing angle mode.

FIG. 5A is a graph showing transmittance property of a image-displayingsub pixel and a viewing angle-adjusting sub pixel of a liquid crystaldisplay device in a narrow viewing angle mode according to a firstembodiment of the present invention and FIG. 5B is a graph showingcontrast ratio property of a liquid crystal display device in a narrowviewing angle according to a first embodiment of the present invention.X-axes of the graphs represent a right-left viewing angle or an up-downviewing angle, and y-axes of the graphs represents a relativetransmittance of arbitrary unit (A.U.) and a relative contrast ratio ofarbitrary unit (A.U.).

In FIG. 5A, when the LCD device is operated in the narrow viewing anglemode, the image-displaying sub pixel such as the first, second and thirdsub pixels SP1, SP2 and SP3 (of FIG. 2) has transmittances correspondingto the data signal, for example, the white or the black. The viewingangle-adjusting sub pixel such as the fourth sub pixel SP4 (of FIG. 2)has the maximum transmittance within a predetermined viewing anglerange. The white of the LCD device corresponds to the sum of thetransmittance of the white of the image-displaying sub pixel and thetransmittance of the viewing angle-adjusting sub pixel in the narrowviewing angle mode, and the black of the LCD device corresponds to thesum of the transmittance of the black of the image-displaying sub pixeland the transmittance of the viewing angle-adjusting sub pixel in thenarrow viewing angle mode. Accordingly, the white of the LCD device issubstantially the same as the white of the image-displaying sub pixel,and the black of the LCD device is substantially the same as thetransmittance of the image-displaying sub pixel in the narrow viewingangle mode.

As shown in FIG. 5B, the contrast ratio of the LCD device has a maximumvalue of about 130 at the front viewing angle (a viewing angle of about0°). In addition, the contrast ratio of the LCD device is over about 10at a right-left viewing angle or an up-down viewing angle of about −20°to about +20°, which may be referred to as a front viewing angle range(the contrast ratio is over about 30 at a right-left viewing angle or anup-down viewing angle of about −10° to about +10°), and is substantiallyabout 0 at a right-left viewing angle or an up-down viewing anglesmaller than about −20° and greater than about +20°. Accordingly, theLCD device displays images with a relatively high contrast ratio withinthe front viewing angle range, and displays images with a relatively lowcontrast ratio within the predetermined viewing angle range (forexample, smaller than about −20° and greater than about +20°). As aresult, a user located within the predetermined viewing angle range doesnot recognize the images, thereby the LCD device displaying the imagesonly within the front viewing angle range in the narrow viewing anglemode.

FIG. 6 is a view showing images displayed by a liquid crystal displaydevice in a narrow viewing angle mode according to a first embodiment ofthe present invention.

In the LCD device according to the first embodiment of the presentinvention, first, second, third and fourth data signals are applied tofirst, second, third and fourth sub pixels SP1, SP2, SP3 and SP4 (ofFIG. 2), respectively. When the LCD device is operated in the wideviewing angle mode, the image-displaying sub pixels such as the first,second and third sub pixels SP1, SP2 and SP3 display a first image of awide viewing angle, and the viewing angle-adjusting sub pixel such asthe fourth sub pixel SP4 displays the black within an entire viewingangle range. As a result, the LCD device displays the first image with awide viewing angle.

As shown in FIG. 6, when the LCD device is operated in the narrowviewing angle, the image-displaying sub pixels such as the first, secondand third sub pixels SP1, SP2 and SP3 display the first image of thewide viewing angle, and the viewing angle-adjusting sub pixel such asthe fourth sub pixel SP4 displays the black within a front viewing anglerange and a second image of single color of white within a predeterminedviewing angle range. Since the first image is not recognized within thepredetermined viewing angle range due to reduction in contrast ratio bydisturbance of the second image, the LCD device displays the first imagewithin the front viewing angle range, i.e., with a narrow viewing angle.The fourth data signals applied to the fourth sub pixels SP4 of the LCDdevice may have an equal voltage such that the second image correspondsto the white of uniform brightness.

FIG. 7 is a view showing images displayed by a liquid crystal displaydevice in a narrow viewing angle mode according to a second embodimentof the present invention, and FIG. 8 is a graph showing transmittanceproperty of a viewing angle-adjusting sub pixel of a liquid crystaldisplay device according to a second embodiment of the presentinvention.

In the LCD device according to the second embodiment of the presentinvention, first, second, third and fourth data signals are applied tofirst, second, third and fourth sub pixels SP1, SP2, SP3 and SP4 (ofFIG. 2), respectively. The operation of the LCD device of the secondembodiment in a wide viewing angle mode is substantially the same as theoperation of the LCD device of the first embodiment in a wide viewingangle mode. Accordingly, when the LCD device is operated in the wideviewing angle mode, the image-displaying sub pixels such as the first,second and third sub pixels SP1, SP2 and SP3 display a first image of awide viewing angle, and the viewing angle-adjusting sub pixel such asthe fourth sub pixel SP4 displays the black within an entire viewingangle range. As a result, the LCD device displays the first image with awide viewing angle.

As shown in FIG. 7, when the LCD device is operated in the narrowviewing angle, the image-displaying sub pixels such as the first, secondand third sub pixels SP1, SP2 and SP3 display the first image of thewide viewing angle, and the viewing angle-adjusting sub pixel such asthe fourth sub pixel SP4 displays the black within a front viewing anglerange and a second image (e.g., characters or text) different from thefirst image within a predetermined viewing angle range. Accordingly, thefirst, second and third data signals corresponding to the first imageare applied to the first, second and third sub pixels SP1, SP2 and SP3,respectively, and the fourth data signal corresponding to the secondimage is applied to the fourth sub pixel SP4. Since the first image isnot recognized within the predetermined viewing angle range due toreduction in contrast ratio by disturbance of the second image, the LCDdevice displays the first image within the front viewing angle range,i.e., with a narrow viewing angle.

The fourth data signals respectively applied to the fourth sub pixelsSP4 of the LCD device through TFTs may have various voltages such thatthe second image has a shape such as characters or a text by differencesin grays. As shown in FIG. 8, when first, second, third and fourthvoltages different from each other are applied to the fourth sub pixelsSP4 of the LCD device, the fourth sub pixels SP4 display a black oftransmittance of about 0 within the front viewing angle range and fourgrays corresponding to transmittances of about 0, about 40, about 80 andabout 100 within the predetermined viewing angle range (e.g., at theviewing angle of about −45° and about +45°). Accordingly, the LCD devicedisplays the second images having differences in grays within thepredetermined viewing angle range.

FIGS. 9 and 10 are plan views showing an array substrate and a colorfilter substrate, respectively, of a liquid crystal display deviceaccording to a third embodiment of the present invention. In addition,FIG. 11 is a cross-sectional view, which is taken along a line XI-XI ofFIGS. 9 and 10, showing a liquid crystal display device according to athird embodiment of the present invention.

In FIGS. 9 and 11, an LCD device 200 includes first and secondsubstrates 205 and 245 facing and spaced apart from each other. Thefirst substrate 205 includes first, second, third and fourth sub pixelsSP1, SP2, SP3 and SP4. A first gate line 210 a, a second gate line 210 band a gate electrode 212 are formed on the first substrate 205. Althoughthe gate electrode 212 is connected to the second gate line 210 b in thefourth sub pixel SP4 in FIG. 11, each of the first, second and third subpixels SP1, SP2 and SP3 includes the gate electrode. A gate insulatinglayer of one of inorganic and organic insulating materials is formed onthe first gate line 210 a, the second gate line 210 b and the gateelectrode 212, and an active layer 216 of a semiconductor material suchas amorphous silicon (a-Si:H) is formed on the gate insulating layer 214over the gate electrode 212. Although not shown in FIG. 11, each of thefirst, second and third sub pixels SP1, SP2 and SP3 includes the activelayer. Source and drain electrodes 218 a and 218 b of a conductivematerial are formed on the active layer 216 to be spaced apart from eachother. The gate electrode 212, the active layer 216, the sourceelectrode 218 a and the drain electrode 218 b constitute a fourth thinfilm transistor (TFT) T4. In addition, the first, second and third subpixels SP1, SP2 and SP3 include the first, second and third TFTs,respectively.

First and second data lines 220 a and 220 b crossing the first andsecond gate lines 210 a and 210 b to define the first, second, third andfourth sub pixels SP1, SP2, SP3 and SP4 are formed on the gateinsulating layer 214. The source electrode 218 a is connected to thesecond data line 221 b. A passivation layer 219 of one of inorganic andorganic insulating materials is formed on the first data line 220 a, thesecond data line 220 b, the source electrode 218 a and the drainelectrode 218 b. The passivation layer 219 has a drain contact hole 219a exposing the drain electrode 218 b. First, second, third and fourthpixel electrodes 230 a, 230 b, 230 c and 230 d of a transparentconductive material are formed on the passivation layer 219 in thefirst, second, third and fourth sub pixels SP1, SP2, SP3 and SP4,respectively. Each of the first, second, third and fourth pixelelectrodes 230 a, 230 b, 230 c and 230 d is connected to thecorresponding drain electrode in each of the first, second, third andfourth sub pixels SP1, SP2, SP3 and SP4. For example, the fourth pixelelectrode 230 d is connected to the drain electrode 218 b through thedrain contact hole 219 a in the fourth sub pixel SP4.

The first pixel electrode 230 a connected to the first TFT T1 is formedin the first sub pixel SP1 defined by the first gate line 210 a and thefirst data line 220 a, and a first data signal is applied to the firstpixel electrode 230 a. Similarly, the second pixel electrode 230 bconnected to the second TFT T2 is formed in the second sub pixel SP2defined by the first gate line 210 a and the second data line 220 b, anda second data signal is applied to the second pixel electrode 230 b. Inaddition, the third pixel electrode 230 c connected to the third TFT T3is formed in the third sub pixel SP3 defined by the second gate line 210b and the first data line 220 a, and a third data signal is applied tothe third pixel electrode 230 c. Finally, the fourth pixel electrode 230d connected to the fourth TFT T4 is formed in the fourth sub pixel SP4defined by the second gate line 210 b and the second data line 220 b,and a fourth data signal is applied to the fourth pixel electrode 230 d.

Here, the first, second, third and fourth pixel electrodes 230 a, 230 b,230 c and 230 d are spaced apart from one another, and a gap between theadjacent two pixel electrodes may be regarded as a field distortionmeans such as a slit. For example, an outer portion of an upper side ofthe fourth pixel electrode 230 d near the first gate line 210 a mayfunction as a first pixel slit 232 a and an outer portion of a lowerside of the fourth pixel electrode 230 d near the second gate line 210 bmay function as a second pixel slit 232 b.

In FIGS. 10 and 11, a second substrate 245 of the LCD device 200includes the first, second, third and fourth sub pixels SP1, SP2, SP3and SP4. A black matrix 250 corresponding to the first and second gatelines 210 a and 210 b, the first and second data lines 220 a and 220 b,and the first to fourth TFTs T1 to T4 of the first substrate 205 isformed on an inner surface of the second substrate 245. A color filterlayer including first, second and third color filters 260 a, 260 b and260 c is formed on the black matrix 250. The first, second and thirdcolor filters 260 a, 260 b and 260 c are formed on the inner surface ofthe second substrate 245 in the first, second and third sub pixels SP1,SP2 and SP3, respectively. Since the fourth sub pixel SP4 is used as aviewing angle-adjusting sub pixel, display of a color image is notrequired in the fourth sub pixel SP4. In addition, since transmittanceincreases by omission of the color filter layer, the color filter layeris not formed in the fourth sub pixel SP4. In another embodiment,however, the color filter layer of a transparent material (i.e., atransparent layer) may be formed in the fourth sub pixel SP4 to improveuniformity of cell gap of the LCD device and planarization property ofthe color filter layer.

A common electrode 270 is formed on the first, second and third colorfilter layer 260 a, 260 b and 260 c and the second substrate in thefourth sub pixel SP4. First, second, third and fourth common protrusions280 a, 280 b, 280 c and 280 d of a dielectric material are formed on thecommon electrode 270 in the first, second, third and fourth sub pixelsSP1, SP2, SP3 and SP4, respectively. The first, second, third and fourthcommon protrusions 280 a, 280 b, 280 c and 280 d are used as a fielddistortion means. The first, second and third protrusions 280 a, 280 band 280 c each having a hemispheric shape are formed in a centralportion of the first, second and third sub pixels SP1, SP2 and SP3,respectively. In addition, the fourth common protrusion 280 d having abar shape along a horizontal direction parallel to the gate line isformed in a central portion of the fourth sub pixel SP4.

The first and second substrates 205 and 245 are attached such that thefourth pixel electrode 230 d faces the common electrode 270, and aliquid crystal layer 290 including negative type liquid crystalmolecules having a negative dielectric constant anisotropy is formedbetween the first and second substrates 205 and 245. Although not shownin FIGS. 9, 10 and 11, first and second polarizing plates may be formedon outer surfaces of the first and second substrates 205 and 245,respectively, and a polarization axis of the first polarizing plate maybe perpendicular to a polarization axis of the second polarizing plate.For example, the first polarizing plate on the outer surface of thefirst substrate 205 may have a polarization axis along a horizontaldirection parallel to the gate line and the second polarization plate onthe outer surface of the second substrate 245 may have a polarizationaxis along a vertical direction parallel to the data line.

When the gate signal is sequentially applied to the first and secondgate lines 210 a and 210 b, the first, second, third and fourth TFTs T1,T2, T3 and T4 are turned on and the first, second, third and fourth datasignals are applied to the first, second, third and fourth pixelelectrodes 230 a, 230 b, 230 c and 230 d, respectively, through thefirst and second data lines 220 a and 220 b. The liquid crystalmolecules in the liquid crystal layer 290 are re-aligned by the electricfield generated between each of the first, second, third and fourthpixel electrodes 230 a, 230 b, 230 c and 230 d and the common electrode270. The electric field is distorted by the first, second, third andfourth common protrusions 280 a, 280 b, 280 c and 280 d and the pixelslits. Accordingly, the liquid crystal molecules are re-aligned to havea fan shape with each of the first, second and third common protrusions280 a, 280 b and 280 c as a center in each of the first, second andthird sub pixels SP1, SP2 and SP3 and a multi-domain is formed in eachof the first, second and third sub pixels SP1, SP2 and SP3. In addition,the liquid crystal molecules are re-aligned to have a symmetric shapewith respect to the fourth common protrusion 280 d and a two-domain isformed in the fourth sub pixel SP4. As a result, the first, second andthird sub pixels SP1, SP2 and SP3 display the first image of a wideviewing angle, and the fourth sub pixel SP4 displays the second imagethat has a low transmittance (black) along the front viewing angle rangeand a high transmittance along the predetermined right-left viewingangle range.

The field distortion means of the fourth sub pixel SP4 such as a slitand a protrusion may have various shapes in another embodiment. FIGS. 12and 13 are plan views showing an array substrate and a color filtersubstrate, respectively, of a liquid crystal display device according toa fourth embodiment of the present invention. Since first, second andthird sub pixel of the LCD device according to the fourth embodiment arethe same as those of the LCD device according to the third embodiment,illustrations will be omitted.

In FIGS. 12 and 13, first, second, third and fourth pixel electrodes 330a, 330 b, 330 c and 330 d are spaced apart from one another, and a gapbetween the adjacent two pixel electrodes may be regarded as a fielddistortion means such as a slit. For example, an outer portion of a leftside of the fourth pixel electrode 330 d near a first gate line 310 amay function as a first pixel slit 332 a and an outer portion of a rightside of the fourth pixel electrode 330 d near a second gate line 310 bmay function as a second pixel slit 332 b. In addition, first, second,third and fourth common protrusions 380 a, 380 b, 380 c and 380 d of adielectric material as a field distortion means are formed on a commonelectrode 370 in first, second, third and fourth sub pixels SP1, SP2,SP3 and SP4, respectively. The first, second and third commonprotrusions 380 a, 380 b and 380 c each having a hemispheric shape areformed in a central portion of the first, second and third sub pixelsSP1, SP2 and SP3, respectively. The fourth common protrusion 380 dhaving a bar shape along a vertical direction parallel to the data lineis formed in a central portion of the fourth sub pixel SP4.

The operation of the LCD device according to the fourth embodiment issimilar to the operation of the LCD device according to the thirdembodiment. The liquid crystal molecules are re-aligned by the electricfield generated between each of the first, second, third and fourthpixel electrodes 330 a, 330 b, 330 c and 330 d and the common electrode370. The electric field is distorted by the first, second, third andfourth common protrusions 380 a, 380 b, 380 c and 380 d and the pixelslits. Accordingly, the liquid crystal molecules are re-aligned to havea fan shape with each of the first, second and third common protrusions380 a, 380 b and 380 c as a center in each of the first, second andthird sub pixels SP1, SP2 and SP3 and a multi-domain is formed in eachof the first, second and third sub pixels SP1, SP2 and SP3. In addition,the liquid crystal molecules are re-aligned to have a symmetric shapewith respect to the fourth common protrusion 380 d and a two-domain isformed in the fourth sub pixel SP4. As a result, the first, second andthird sub pixels SP1, SP2 and SP3 display the first image of a wideviewing angle, and the fourth sub pixel SP4 displays the second imagethat has a low transmittance (black) along the front viewing angle rangeand a high transmittance along the predetermined up-down viewing anglerange.

Consequently, the LCD device having the fourth common protrusion of avertical bar shape according to the fourth embodiment is switchedbetween the wide viewing angle mode and the narrow viewing angle mode tocontrol the up-down viewing angle, while the LCD device having thefourth common protrusion of a horizontal bar shape according to thethird embodiment is switched between the wide viewing angle mode and thenarrow viewing angle mode to control the right-left viewing angle.

Although the field distortion means of a horizontal bar shape or avertical bar shape is formed in each of the fourth sub pixels SP4 of theLCD device according to each of the third and fourth embodiments, thefield distortion means of a horizontal bar shape and a vertical barshape may be alternately formed in each of the fourth sub pixels SP4 ofthe LCD device according to another embodiment. The ratio of thehorizontal bar shape to the vertical bar shape, for example, 1:1, may bedetermined by user's selection.

Further, although the first, second and third image-displaying subpixels SP1, SP2 and SP3 and the fourth viewing angle-adjusting sub pixelSP4 constitute a unit pixel for a color image in each of the third andfourth embodiments, five sub pixels, for example, first, second, thirdand fourth image-displaying sub pixels for red, green, blue and whiteand a fifth viewing angle-adjusting sub pixel may constitute a unitpixel in another embodiment. The area ratio of the four image-displayingsub pixels and the one viewing angle-adjusting sub pixel may bedetermined by user's selection. Moreover, the sub pixels may have one ofa stripe type where the sub pixels are disposed along one line, a quadtype where the sub pixels are disposed in a 2×2 matrix and a pentiletype where a fifth sub pixel is disposed at a center of first to fourthsub pixels in a 2×2 matrix.

FIGS. 14, 15 and 16 are cross-sectional views showing liquid crystaldisplay devices according to fifth, sixth and seventh embodiments of thepresent invention, respectively.

In FIG. 14, an LCD device 400 includes first and second substrates 405and 445 and a liquid crystal layer 490 between the first and secondsubstrates 405 and 445. First, second, third and fourth pixel electrodes(not shown, 430 b, not shown, 430 d) are formed over an inner surface ofthe first substrate 405 in first, second, third and fourth sub pixelsSP1, SP2, SP3 and SP4, respectively, and common electrode 470 is formedover an inner surface of the second substrate 445. The first, second,third and fourth pixel electrodes (not shown, 430 b, not shown and 430d) are spaced apart from one another, and a gap between the adjacent twopixel electrodes may be regarded as a field distortion means such as aslit. For example, an outer portion of an upper side of the fourth pixelelectrode 430 d near a first gate line 410 a may function as a firstpixel slit 432 a and an outer portion of a lower side of the fourthpixel electrode 430 d near a second gate line (not shown) may functionas a second pixel slit 432 b. In addition, first, second, third andfourth common slits (not shown, 480 b, not shown and 480 d) as a fielddistortion means are formed in the common electrode 470 in first,second, third and fourth sub pixels SP1, SP2, SP3 and SP4, respectively.The first, second and third common slits (not shown, 480 b and notshown) each having a circular shape are formed in a central portion ofthe first, second and third sub pixels SP1, SP2 and SP3, respectively.The fourth common slit 480 d having a bar shape along a horizontaldirection parallel to the gate line is formed in a central portion ofthe fourth sub pixel SP4.

The liquid crystal molecules in the liquid crystal layer 490 arere-aligned by the electric field generated between each of the first,second, third and fourth pixel electrodes (not shown, 430 b, not shownand 430 d) and the common electrode 470. The electric field is distortedby the first, second, third and fourth common slits (not shown, 480 b,not shown and 480 d) and the pixel slits. Accordingly, the liquidcrystal molecules are re-aligned to have a fan shape with each of thefirst, second and third common slits (not shown, 480 b and not shown) asa center in each of the first, second and third sub pixels SP1, SP2 andSP3 and a multi-domain is formed in each of the first, second and thirdsub pixels SP1, SP2 and SP3. In addition, the liquid crystal moleculesare re-aligned to have a symmetric shape with respect to the fourthcommon slit 480 d and a two-domain is formed in the fourth sub pixelSP4. As a result, the first, second and third sub pixels SP1, SP2 andSP3 display the first image of a wide viewing angle, and the fourth subpixel SP4 displays the second image that has a low transmittance (black)along the front viewing angle range and a high transmittance along thepredetermined up-down viewing angle range.

In FIG. 15, an LCD device 500 includes first and second substrates 505and 545 and a liquid crystal layer 590 between the first and secondsubstrates 505 and 545. First, second, third and fourth pixel electrodes(not shown, 530 b, not shown, 530 d) are formed over an inner surface ofthe first substrate 505 in first, second, third and fourth sub pixelsSP1, SP2, SP3 and SP4, respectively, and common electrode 570 is formedover an inner surface of the second substrate 545. Pixel protrusions ofa dielectric material as a field distortion means are formed on thefirst, second, third and fourth pixel electrodes (not shown, 530 b, notshown and 530 d. For example, a first pixel protrusion 532 a is formedon an upper side of the fourth pixel electrode 530 d near a first gateline 510 a and a second pixel protrusion 532 b is formed on a lower sideof the fourth pixel electrode 530 d near a second gate line (not shown).In addition, first, second, third and fourth common protrusions (notshown, 580 b, not shown and 580 d) as a field distortion means areformed on the common electrode 570 in first, second, third and fourthsub pixels SP1, SP2, SP3 and SP4, respectively. The first, second andthird common protrusions (not shown, 580 b and not shown) each having acircular shape are formed in a central portion of the first, second andthird sub pixels SP1, SP2 and SP3, respectively. The fourth commonprotrusion 580 d having a bar shape along a horizontal directionparallel to the gate line is formed in a central portion of the fourthsub pixel SP4.

The liquid crystal molecules in the liquid crystal layer 590 arere-aligned by the electric field generated between each of the first,second, third and fourth pixel electrodes (not shown, 530 b, not shownand 530 d) and the common electrode 570. The electric field is distortedby the first, second, third and fourth common protrusions (not shown,580 b, not shown and 580 d) and the pixel protrusions. Accordingly, theliquid crystal molecules are re-aligned to have a fan shape with each ofthe first, second and third common protrusions (not shown, 580 b and notshown) as a center in each of the first, second and third sub pixelsSP1, SP2 and SP3 and a multi-domain is formed in each of the first,second and third sub pixels SP1, SP2 and SP3. In addition, the liquidcrystal molecules are re-aligned to have a symmetric shape with respectto the fourth common protrusion 580 d and a two-domain is formed in thefourth sub pixel SP4. As a result, the first, second and third subpixels SP1, SP2 and SP3 display the first image of a wide viewing angle,and the fourth sub pixel SP4 displays the second image that has a lowtransmittance (black) along the front viewing angle range and a hightransmittance along the predetermined up-down viewing angle range.

In FIG. 16, an LCD device 600 includes first and second substrates 605and 645 and a liquid crystal layer 690 between the first and secondsubstrates 605 and 645. First, second, third and fourth pixel electrodes(not shown, 630 b, not shown, 630 d) are formed over an inner surface ofthe first substrate 605 in first, second, third and fourth sub pixelsSP1, SP2, SP3 and SP4, respectively, and common electrode 670 is formedover an inner surface of the second substrate 645. Pixel protrusions ofa dielectric material as a field distortion means are formed on thefirst, second, third and fourth pixel electrodes (not shown, 630 b, notshown and 630 d. For example, a first pixel protrusion 632 a is formedon an upper side of the fourth pixel electrode 630 d near a first gateline 610 a and a second pixel protrusion 532 b is formed on a lower sideof the fourth pixel electrode 630 d near a second gate line (not shown).In addition, first, second, third and fourth common slits (not shown,680 b, not shown and 680 d) as a field distortion means are formed inthe common electrode 670 in first, second, third and fourth sub pixelsSP1, SP2, SP3 and SP4, respectively. The first, second and third commonslits (not shown, 680 b and not shown) each having a circular shape areformed in a central portion of the first, second and third sub pixelsSP1, SP2 and SP3, respectively. The fourth common slit 680 d having abar shape along a horizontal direction parallel to the gate line isformed in a central portion of the fourth sub pixel SP4.

The liquid crystal molecules in the liquid crystal layer 690 arere-aligned by the electric field generated between each of the first,second, third and fourth pixel electrodes (not shown, 630 b, not shownand 630 d) and the common electrode 670. The electric field is distortedby the first, second, third and fourth common slits (not shown, 680 b,not shown and 680 d) and the pixel protrusions. Accordingly, the liquidcrystal molecules are re-aligned to have a fan shape with each of thefirst, second and third common slits (not shown, 580 b and not shown) asa center in each of the first, second and third sub pixels SP1, SP2 andSP3 and a multi-domain is formed in each of the first, second and thirdsub pixels SP1, SP2 and SP3. In addition, the liquid crystal moleculesare re-aligned to have a symmetric shape with respect to the fourthcommon slit 680 d and a two-domain is formed in the fourth sub pixelSP4. As a result, the first, second and third sub pixels SP1, SP2 andSP3 display the first image of a wide viewing angle, and the fourth subpixel SP4 displays the second image that has a low transmittance (black)along the front viewing angle range and a high transmittance along thepredetermined up-down viewing angle range.

Although a single common slit of a circular shape or a single commonprotrusion of a hemispheric shape is formed in a central portion of eachof the first, second and third image-displaying sub pixels SP1, SP2 andSP3 in the LCD device according to one of the third to seventhembodiment, at least two common slit or at least two common protrusionof one of a circular shape and a polygonal shape may be formed in eachof the first, second and third image-displaying sub pixels SP1, SP2 andSP3 in the LCD device according to another embodiment.

Further, a pixel slit, a pixel protrusion, a common slit or a commonprotrusion of a slanted bar shape having an angle of about 20° to about70° (preferably an angle of about 40° to about 50°, and specifically, anangle of about 45°) with respect to a horizontal direction parallel tothe gate line may be formed in each of first, second and third subpixels SP1, SP2 and SP3 as a field distortion means in an LCD deviceaccording to another embodiment. Moreover, a pixel slit, a pixelprotrusion, a common slit or a common protrusion of a zigzag bar shapehaving angles of about 20° to about 70° and of about 110° to about 160°(preferably angles of about 40° to about 50° and of about 130° to about140°, and specifically, angles of about 45° and of about 135°) withrespect to a horizontal direction parallel to the gate line may beformed in each of first, second and third sub pixels SP1, SP2 and SP3 asa field distortion means in an LCD device according to anotherembodiment.

In addition, a pixel slit, a pixel protrusion, a common slit or a commonprotrusion of an X shape, a Y shape or a modified Y shape may be formedin each of first, second and third sub pixels SP1, SP2 and SP3 as afield distortion means in an LCD device according to another embodiment.When a pixel slit, a pixel protrusion, a common slit or a commonprotrusion of a slanted bar shape, a zigzag shape, an X shape, a Y shapeor a modified Y shape is used, the pixel slit or the pixel protrusionover the first substrate may have a shape corresponding to and alternatewith the common slit or the common protrusion over the second substrate.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in a liquid crystal displaydevice and a method of driving the liquid crystal display device of thepresent invention without departing from the spirit or scope of theinvention. Thus, it is intended that the present invention cover themodifications and variations of this invention provided they come withinthe scope of the appended claims and their equivalents.

1-12. (canceled)
 13. A method of fabricating a liquid crystal displaydevice, comprising: forming a gate line and a data line on a firstsubstrate, the gate line and the data line crossing each other to definean image-displaying sub pixel and a viewing angle-adjusting sub pixel;forming a thin film transistor connected to the gate line and the dataline; forming a pixel electrode connected to the thin film transistor,the pixel electrode disposed in an entire area of each of theimage-displaying sub pixel and the viewing angle-adjusting sub pixel onan inner surface of the first substrate; forming a color filter layer inthe image-displaying sub pixel on a second substrate; forming a commonelectrode on the color filter layer, the common electrode disposed on anentire inner surface of the second substrate; forming a first fielddistortion means in the image-displaying sub pixel, the first fielddistortion means disposed on the common electrode; forming a secondfield distortion means in the viewing angle-adjusting sub pixel, thesecond field distortion means disposed on each of the pixel electrodeand the common electrode; attaching the first and second substrates suchthat the pixel electrode and the common electrode face each other; andforming a liquid crystal layer having a negative dielectric constantanisotropy between the first and second substrates.
 14. The methodaccording to claim 13, wherein the image-displaying sub pixel has aproperty graph of a transmittance to a viewing angle where thetransmittance has a maximum value at the viewing angle of about 0° anddecreases with increase of the viewing angle.
 15. The method accordingto claim 13, wherein the viewing angle-adjusting sub pixel has aproperty graph of a transmittance to a viewing angle where thetransmittance has a minimum value at the viewing angle of about 0° andmaximum values at first and second viewing angles that are substantiallysymmetrical to each other with respect to the viewing angle of about 0°.16. The method according to claim 13, wherein the first field distortionmeans includes at least one of a common protrusion of a dielectricmaterial on the common electrode and a common slit in the commonelectrode, and second field distortion means includes at least one of apixel protrusion of a dielectric material on the pixel electrode and, apixel slit in the pixel electrode and at least one of, a commonprotrusion of a dielectric material on the common electrode and a commonslit in the common electrode.
 17. The method according to claim 16,wherein the first field distortion means includes at least one havingone of a circular shape and a polygonal shape to form a multi-domain inthe image-displaying sub pixel.
 18. The method according to claim 16,wherein the second field distortion means includes at least one havingone of a horizontal bar shape and a vertical bar shape to form atwo-domain in the viewing angle-adjusting sub pixel.
 19. The methodaccording to claim 13, further comprising forming first and secondpolarizing plates on outer surface of the first and second substrates,respectively, wherein a polarization axis of the first polarizing plateis perpendicular to a polarization axis of the second polarizing plate.20. A method of driving a liquid crystal display device including: firstand second substrates facing and spaced apart from each other, each ofthe first and second substrates having an image-displaying sub pixel anda viewing angle-adjusting sub pixel; a thin film transistorcorresponding to each of the image-displaying sub pixel and the viewingangle-adjusting sub pixel; a liquid crystal display layer between thefirst and second substrates, the liquid crystal layer having a negativedielectric constant anisotropy; a pixel electrode in an entire area ofeach of the image-displaying sub pixel and the viewing angle-adjustingsub pixel on an inner surface of the first substrate; a common electrodeon an entire inner surface of the second substrate; a first fielddistortion means in the image-displaying sub pixel, the first fielddistortion means formed on the common electrode; and a second fielddistortion means in the viewing angle-adjusting sub pixel, the secondfield distortion means formed on each of the pixel electrode and thecommon electrode, comprising: when the liquid crystal display device isoperated in a wide viewing angle mode, displaying a first image of awide viewing angle by the image-displaying sub pixel; and displaying ablack at an entire viewing angle range by the viewing angle-adjustingsub pixel, when the liquid crystal display device is operated in anarrow viewing angle mode, displaying the first image of the wideviewing angle by the image-displaying sub pixel; and displaying theblack within a front viewing angle range and a second image within apredetermined viewing angle range by the viewing angle-adjusting subpixel.
 21. The method according to claim 20, wherein theimage-displaying sub pixel has a property graph of a transmittance to aviewing angle where the transmittance has a maximum value at the viewingangle of about 0° and decreases with increase of the viewing angle. 22.The method according to claim 20, wherein the viewing angle-adjustingsub pixel has a property graph of a transmittance to a viewing anglewhere the transmittance has a minimum value at the viewing angle ofabout 0° and maximum values at first and second viewing angles that aresubstantially symmetrical to each other with respect to the viewingangle of about 0°.
 23. The method according to claim 20, wherein thesecond image is one of a white and a text.